1. Field of the Invention
The present invention relates to a resinous composition based on a saponified product of ethylene-vinyl acetate copolymer (referred to as EVOH hereinafter) and to an impact-resistant molded article and container made of said resinous composition.
2. Description of the Prior Art
EVOH is a thermoplastic resin which is incomparably superior to other resins in oil resistance, organic solvent resistance, stiffness, hardness, abrasion resistance, and oxygen barrier properties. However, it has a disadvantage of being poor in impact resistance and hard and brittle. There are some known methods for improving the impact resistance of EVOH by blending a rubber-like material. For example, there is disclosed in Japanese Patent Publication No. 3185/1967 the improvement by blending an ethylene-vinyl carboxylate copolymer or ethylene-acrylate copolymer. These methods are still inadequate in improvement in impact resistance and moldability because of the poor dispersion of the resin to be blended.
Another example of the blended EVOH is disclosed in Japanese Patent Laid-open No. 131033/1980. According to the disclosure, a resinous composition is produced by blending 50 to 97 parts by weight of EVOH and 50 to 3 parts by weight of thermoplastic polyolefin copolymer having the carbonyl group (--C.dbd.O) derived from an unsaturated carboxylic acid or anhydride thereof. (Examples of such copolymers include maleic anhydride-grafted polyethylene, ionomer, ethylene-vinyl acetate copolymer, and ethylene-acrylate copolymer.) This resinous composition finds use as packaging materials that can be easily cut with an edged tool. Even this resinous composition lacks satisfactory impact resistance and forms gel at the time of molding.
Further Japanese Patent Laid-open No. 86579/1975 discloses a composition composed of EVOH and a polyolefin (e.g., polyethylene) modified with an unsaturated polybasic carboxylic acid. It also discloses a multi-layered blow-molded container made by coextrusion of the composition and a polyolefin. They still have the same disadvantages as mentioned above. This will be understood from the comparative examples mentioned later.